Supporting wireway hangers on board ship is old and well known. Forming such support often included the attaching of a bar or square tubing to a metal structure that may be an overhead or a bulkhead. Typically, the wireway hangers found on most ships are hung from the steel overhead at the ends of two lengths of bar or square tubing. The bar or tubing forms the support leg for the hanger that has horizontal tiers consisting of bars or rods fastened to the support legs for contact support with the wires or cables that are to be secured spaced from but close to the overhead. The same method could be utilized to secure pipes, ducts or items such as switchboards to the bulkhead or overhead or deck below.
In the typical conventional application for construction of wireway hangers, the bar or tubing used will form the support leg for the tiers. The bar or tubing is secured to the overhead or bulkhead or other metal structure by welding. The weld for securing the bar or tubing is typically a tack weld at a couple of points around the circumference of the bar or tubing, or possibly a complete parametric fillet weld. Usually this method requires one person to hold the lengths of bar or tubing to the overhead with tiers attached or with a special jig while a welder tacks the bar or tubing to the metal structure. The jig supports the two lengths of bar or tubing to ensure that they are positioned correctly. The jig is then removed and, if necessary, the welds are completed. Tack welds and fillet welds are made by manual welding. If the overhead is of a special material, for example, high yield steel, special welding procedures must be followed, which may be very cumbersome and time consuming requiring specially qualified welders and lengthy inspections and auditing steps. Most metal structures require heating prior to welding and this can be very expensive.
Once the vertical legs are secured to the overhead or bulkhead or other metal structure, cross pieces or tiers can be secured to these vertical legs by any appropriate means. It is these cross pieces or tiers that support the wires or cables. A series of such supports is called a wireway for the holding of wire or cable. Whether the objects to be secured to the overhead or bulkhead are wires, pipes, conduits or other ducts is not important because they have the common requirement of a secure fixed location spaced from the overhead, bulkhead or other metal structure.
In certain shipbuilding operations, it may be required to move the wireway support at a later date. This operation requires that the bar or tubing used to form legs will have to be cut from the overhead and the welds that previously held such legs to the metal structure would have to be ground until smooth at the surface of the metal structure. Should the overhead or bulkhead be of a special metallic material, cumbersome weld repair, inspection and auditing steps may again be required adding substantially to the cost of the procedure.
It is proposed with this invention to substitute a stud weld for the manual weld. While variously shaped studs have been utilized in the past in welding using a stud gun, the shape of the stud base for the end weld has been found to be important for the stability of the weld as well as the ease of achieving the weld. The round shape of the end being welded to the metal structure has been found to be the most stable and most desirable shape for the end weld. The round or cylindrical shape of the stud, however, is not found desirable for supporting a leg upon which a tier is to be mounted for construction of a wire hanger. Additionally, the prior art studs would not have bores on planar surfaces that enable a support leg to be bolted to the installed stud.
The known prior art does not disclose the combination of a round and square stud having bores for placement of a support leg. For instance, Jenkins U.S. Pat. No. 3,506,227 discloses either a round threaded stud or a simple flat bar stud neither of which would serve the purposes of the present invention. Neither flat bar nor angle bar nor square tubing can easily be attached to a threaded stud. The rectangular surface connection for the flat bar stud would not be a secure weld and could not be utilized to achieve the secure fastening of the stud of the present invention. Moreover, such a flat bar stud is stiff in only one direction.
The patent to Logan U.S. Pat. No. 3,279,517 discloses a welding stud for attachment to convex surfaces and does not disclose the stud nor the purposes to which the present invention is directed.
Jenkins U.S. Pat. No. 3,517,901 discloses a pipe hanger using a stud having a rectangular cross section that would not provide the stable fastening of the present invention.
Rondeau U.S. Pat. No. 3,760,143 shows an alternative welding stud unlike the welding stud of the present invention.